For reference to an autoignition two-stroke internal combustion engine of the type which utilizes working chambers which have a generally rectangular cross section and pistons which also have a generally rectangular outline and operate with seals which lie in respective planes and are of the rib or bar type, reference may be had to my U.S. Pat. No. 5,148,778 issued Sept. 22, 1992.
In the two-stroke internal combustion engine field, it is known to provide rotary sleeve valves which serve for material exchange in the system, i.e. admitting fresh air to the working chamber as a combustion-sustaining gas and enabling exhaust gas formed in the combustion, ignition or explosion process to be discharged.
These systems alleviate the disadvantage of fresh-air loss in more conventional three-passage internal combustion engines in which the material exchange is effected exclusively by an appropriate travel to the combustion past passages in the wall of the respective working chamber.
It is also known to provide a two-stroke internal combustion engine with a centrifugal or turbocompressor which supplies the fresh air or fresh gas to flush the working chamber and for supercharging purposes.
It is also known to provide a high efficiency internal combustion engine by providing oscillating pistons in partial cylinders enabling a secondary expansion of the working gasses. In this case, diffusion of exhaust gas into fresh gas is intentionally provided to reduce NO.sub.x release which cannot be readily achievable with two-stroke engines operating with valves.
In four-stroke diesel and autoengines, turbo supercharging has been increasingly used in recent years. In this case, turbocompressors driven by exhaust gas are used to increase the filling of the working cylinder with the compressed air or the fuel/air mixture and thus bring about an improvement in power output and fuel efficiency. However, with these systems, there is a thermal coupling of the supercharger and the expansion turbine which requires an expensive supercharging air cooling.
It should also be mentioned that an additional exhaust gas turbine to increase power output has been provided heretofore and is coupled with the crankshaft by a transmission. This contributes to an overall efficiency increase of the engine. With diesel engines or trucks, it is possible to increase the overall efficiency in this manner to say 47%.